On August 1, 2008, iLounge published iPhone Gems: Every Sudoku Game, Reviewed, a feature article looking at 23 different Sudoku releases for the iPhone OS. This review focuses on Trivial Sudoku ($1) by Trivial Technology; you can read the full article, with screenshots of all of the games together, through the link above. A collective screenshot below shows you some of the other Sudoku interfaces you can expect to find in these titles.

If you’re reading this article, you probably already know that Sudoku is a one-screen puzzle game based upon a 9-by-9 grid that’s partially filled with numbers. The objective is to fill the empty spaces of the grid with single digit numbers so that the same digit does not appear twice on any horizontal or vertical line. Additionally, the same number should not appear twice in any of nine 3-by-3 mini grids on the screen.

iLounge’s top-ranked Sudoku games are ones that offered fully-functional renditions of the game, with impressive interfaces, bonus features, user customization, and pricing as of the time we tested them. The fewer of these features a given game had, the lower it rated. While updates to these games may well be released over time, and their features may change, we couldn’t wait around forever for bad or so-so titles to catch up with ones that were already good or great.

Trivial Sudoku is another plain jane version of the game. Three difficulty levels are your primary options, along with a training mode that tells you immediately if you’ve made a mistake, and the ability to enable or disable marking of guesses in small characters. There are no visual or audio frills; you provide the iPod soundtrack yourself. There are only 75 puzzles here, a factor that detracts from what was otherwise just above demo-quality software.

Editors' Note: iLounge only reviews products in "final" form, but many companies now change their offerings - sometimes several times - after our reviews have been published.
This iLounge article provides more information on this practice, known as revving.